module.exports = (req,res,next) =>{
  if(req.method==='POST' && req.path==='/login'){
    if(req.body.username==='jack'&&req.body.password==='123456'){
      return res.status(200).json({
        user:{
          token:'123'
        }
      })
    }else{
      return res.status(400).json({message:'用户名or密码错误'})
    }
  }
  next()
}